THE INFLUENCING FACTORS AND KINETICS CHARACTER OF THE REDOX REACTION BETWEEN CATECHIN AND Cr6+

Plant polyphenol can be used as a reductant to prepare chrome tanning agents. The kinetic of the reaction between catechin, which is the procursor of condensed plant polyphenol, and dichromate plays an important role in the study of this preparation. The influencing factors and kinetics character of the redox reaction between catechin and dichromate under different conditions were investegated by spectrophotometry. The results show that redox reaction may be accomplished mostly in 1 min when the reaction begins. The influences of catechin concentration, solution acidity and reaction temperature on redox reaction rate were also investigated. The reaction rate equation at 25℃ was obtained. At temperature over 35℃, there may be multi-radicle reactions which may result in more complicated mechanism that happens between catechin and Cr6+